Why did Portland sign Andre Miller? Are they that down on Rudy and Bayless?

Rudy isn't a PG and the Blazers WERE down on Bayless. He was 3rd string last year and thus he had yet to show much of what we have seen this year. Blazers weren't sure if he'd be ready, traded Sergio, and brought in Andre. Another reason they signed Andre was because they had cap space and were unable to land their targeted free agents (Hedo, Millsap, David Lee). Next summer they would have gone over the cap whether they signed a guy or not due to Roy and Aldridge's extensions, so the Blazers decided to sign the best guy still available in free agency, and that was Andre Miller.